This invention is related to the field of organometal catalyst compositions.
The production of polymers is a multi-billion dollar business. This business produces billions of pounds of polymers each year. Millions of dollars have been spent on developing technologies that can add value to this business.
One of these technologies is called metallocene catalyst technology. Metallocene catalysts have been known since about 1960. However, their low productivity did not allow them to be commercialized. About 1975, it was discovered that contacting one part water with one part trimethylaluminum to form methyl aluminoxane, and then contacting such methyl aluminoxane with a metallocene compound, formed a metallocene catalyst that had greater activity. However, it was soon realized that large amounts of expensive methyl aluminoxane were needed to form an active metallocene catalyst. This has been a significant impediment to the commercialization of metallocene catalysts.
Borate compounds have been used in place of large amounts of methyl aluminoxane. However, this is not satisfactory, since borate compounds are very sensitive to poisons and decomposition, and can also be very expensive.
It should also be noted that having a heterogeneous catalyst is important. This is because heterogeneous catalysts are required for most modern commercial polymerization processes. Furthermore, heterogeneous catalysts can lead to the formation of substantially uniform polymer particles that have a high bulk density. These types of substantially uniform particles are desirable because they improve the efficiency of polymer production and transportation. Efforts have been made to produce heterogeneous metallocene catalysts; however, these catalysts have not been entirely satisfactory.
Therefore, the inventors provide this invention to help solve these problems.
An object of this invention is to provide a process that produces a catalyst composition that can be used to polymerize at least one monomer to produce a polymer.
Another object of this invention is to provide the catalyst composition.
Another object of this invention is to provide a process comprising contacting at least one monomer and the catalyst composition under polymerization conditions to produce the polymer.
Another object of this invention is to provide an article that comprises the polymer produced with the catalyst composition of this invention.
In accordance with one embodiment of this invention, a process to produce a catalyst composition is provided. The process comprises (or optionally, xe2x80x9cconsists essentially ofxe2x80x9d, or xe2x80x9cconsists ofxe2x80x9d) contacting an organometal compound, an organoaluminum compound, and a fluorided silica-alumina to produce the catalyst composition,
wherein said organometal compound has the following general formula:
(X1)(X2)(X3)(X4)M1
xe2x80x83wherein M1 is selected from the group consisting of titanium, zirconium, and hafnium;
wherein (X1) is independently selected from the group consisting of cyclopentadienyls, indenyls, fluorenyls, substituted cyclopentadienyls, substituted indenyls, and substituted fluorenyls;
wherein substituents on the substituted cyclopentadienyls, substituted indenyls, and substituted fluorenyls of (X1) are selected from the group consisting of aliphatic groups, cyclic groups, combinations of aliphatic and cyclic groups, silyl groups, alkyl halide groups, halides, organometallic groups, phosphorus groups, nitrogen groups, silicon, phosphorus, boron, germanium, and hydrogen;
wherein at least one substituent on (X1) can be a bridging group which connects (X1) and (X2);
wherein (X3) and (X4) are independently selected from the group consisting of halides, aliphatic groups, substituted aliphatic groups, cyclic groups, substituted cyclic groups, combinations of aliphatic groups and cyclic groups, combinations of substituted aliphatic groups and cyclic groups, combinations of aliphatic groups and substituted cyclic groups, combinations of substituted aliphatic groups and substituted cyclic groups, amido groups, substituted amido groups, phosphido groups, substituted phosphido groups, alkyloxide groups, substituted alkyloxide groups, aryloxide groups, substituted aryloxide groups, organometallic groups, and substituted organometallic groups;
wherein (X2) is selected from the group consisting of cyclopentadienyls, indenyls, fluorenyls, substituted cyclopentadienyls, substituted indenyls, substituted fluorenyls, halides, aliphatic groups, substituted aliphatic groups, cyclic groups, substituted cyclic groups, combinations of aliphatic groups and cyclic groups, combinations of substituted aliphatic groups and cyclic groups, combinations of aliphatic groups and substituted cyclic groups, combinations of substituted aliphatic groups and substituted cyclic groups, amido groups, substituted amido groups, phosphido groups, substituted phosphido groups, alkyloxide groups, substituted alkyloxide groups, aryloxide groups, substituted aryloxide groups, organometallic groups, and substituted organometallic groups;
wherein substituents on (X2) are selected from the group consisting of aliphatic groups, cyclic groups, combinations of aliphatic groups and cyclic groups, silyl groups, alkyl halide groups, halides, organometallic groups, phosphorus groups, nitrogen groups, silicon, phosphorus, boron, germanium, and hydrogen;
wherein at least one substituent on (X2) can be a bridging group which connects (X1) and (X2);
wherein the organoaluminun compound has the following general formula:
Al(X5)n(X6)3xe2x88x92n
xe2x80x83wherein (X5) is a hydrocarbyl having from 1 to about 20 carbon atoms;
wherein (X6) is a halide, hydride, or alkoxide; and
wherein xe2x80x9cnxe2x80x9d is a number from 1 to 3 inclusive;
wherein the fluorided silica-alumina comprises fluoride, silica, and alumina.
In accordance with another embodiment of this invention, a process is provided comprising contacting at least one monomer and the catalyst composition under polymerization conditions to produce a polymer.
In accordance with another embodiment of this invention, an article is provided. The article comprises the polymer produced in accordance with this invention.
These objects, and other objects, will become more apparent to those with ordinary skill in the art after reading this disclosure.